The killing of a lion named Cecil in Zimbabwe has sparked world-wide outrage, but the largest threat to Africa’s big cats is a human-population boom that is shrinking the animal’s habitat and posing worrying questions about its future in the wild.

The government needs to ban websites and crack down on advertisements that promote the illegal wildlife trade, activists said just days after police in East Java discovered more than 20 critically endangered cockatoos stuffed inside plastic bottles.

The U.N. says up to 100 elephants are being slaughtered a day in Africa by poachers taking part in the illegal ivory trade. Conservationists say that, over the past several years, demand for ivory has been growing, particularly in China. But countries are starting to crack down on tusk trafficking. Watch the video above to learn more.